Ten Democratic hopefuls spoke about climate change and their plans to curtail it at CNN’s Climate Crisis Town Hall on 4 September. The candidates, who answered questions from moderators and audience members for 40 minutes each, addressed concerns, including rising sea levels, regulations on fossil fuel companies, green energy solutions, and the impacts of climate change on people of the world. The event stood in place of a formal debate, as the Democratic National Committee has refused to endorse debates on single-issue topics.

“This feels like something I’ve been waiting for all my career—a substantive discussion of policy where most of the candidates offer new ideas and clearly understand the urgency of the situation.”The candidates all voiced support for rejoining the Paris climate accord, which New Jersey senator Cory Booker said is “the cost of entry” to be on the Democratic ticket.

Although many of the candidates emphasized their support for scientific and research development, with former vice president Joe Biden commenting that “we have to start choosing science over fantasy,” they differed on how they plan to address curbing carbon emissions and mitigating the consequences of climate change.

Kate Marvel, a climate scientist at NASA Goddard Institute for Space Studies, told Eos that she was “impressed with the caliber of questions and the thoughtfulness of many candidates’ responses” at the town hall.

“This feels like something I’ve been waiting for all my career—a substantive discussion of policy where most of the candidates offer new ideas and clearly understand the urgency of the situation,” Marvel noted.

The Struggle Between Urgency and Realism

The candidates spoke about becoming carbon neutral, first in energy generation and then overall, by no later than 2050. South Bend, Ind., mayor Pete Buttigieg said that we must end our dependence on coal “as quickly as humanly possible,” and Massachusetts senator Elizabeth Warren and Vermont senator Bernie Sanders said that most currently proposed timelines were not aggressive enough.

Biden, Minnesota senator Amy Klobuchar, and businessman Andrew Yang put forth that such carbon-free timelines are not realistic given the current science or political structure, a position that elicited frustration from some scientists. Andrea Simonelli, a political science professor at Virginia Commonwealth University in Richmond, called those responses “tone deaf.”

“Biden suggested that the timelines he is using in his plans are because science didn’t have a faster way to transition [or that] there wasn’t the technology yet,” Simonelli explained. “It’s not that we don’t have the tech. We’ve been missing the political will to move on it.”

“Suggesting that we should take more time when the evidence shows we need to move faster minimizes the great risk to all of us as well as the power of American ingenuity,” she added.

Personal Versus Corporate Responsibility

The candidates faced repeated questions on the personal sacrifices that Americans could face in their future plans to address climate change. Former housing and urban development secretary Julián Castro commented that people must strive to take public transit, and California senator Kamala Harris voiced support for plastic straw bans.

Several candidates emphasized that tackling climate change is not entirely dependent on individual actions and instead requires holding corporations responsible.

Warren, for instance, rebuffed a question about consumer choice of light bulbs, saying “I get that people are trying to find the part that they work on” but added “this is exactly what the fossil fuel industry wants us to talk about.”

Arvind Ravikumar, an energy engineer at Harrisburg University of Science and Technology in Pennsylvania, praised her response. “I think Sen. Warren best understands and articulates the need for systemic and institutional change in addressing the climate crisis, and even pointing out the fallacy of focusing on individual actions,” he told Eos.

Buttigieg echoed Warren’s concerns. “No individual can solve this through personal action,” he said. To a question about changing meat consumption in the United States, he responded, “Of course we need balance in all our consumption patterns,” and said that questioners should stop repeating Republican talking points.

Leah Stokes, an assistant professor in the Department of Political Science at the University of California, Santa Barbara, said that despite CNN’s repeated questions on individual responsibility, “overall, I think the candidates did a good job of pushing back against that framing.”

Resilience Versus Retreat

When it came to the question of whether residents should move away from areas vulnerable to natural disasters or build up resilience to them—flight or fight—candidates were split. Those in the fight camp, like Booker, argued that regardless of sea level rise communities will face natural hazards that they must prepare for. “We don’t want to wait until there’s a natural disaster to actually make our communities more sustainable,” Castro mentioned earlier in the evening.

Castro also endorsed the idea of protecting more people with subsidized flood insurance, an approach that Naomi Oreskes, a professor of the history of science at Harvard University, called “a mistake.”

“This should open a discussion about the future of disaster insurance, immigration policy, and disaster preparedness.”“I would rather he had suggested paying for necessary relocation out of his carbon pollution fee,” Oreskes commented during the town hall.

Other candidates also saw this stance as a temporary solution at best. It is “pretty stupid” to keep paying people to rebuild where things keep getting destroyed, according to Sanders. Both he and Warren supported the idea that people living in affected areas should be offered monetary support to relocate to safer areas. Temporary protected status and a special asylum status must be offered to international climate refugees around the world, said former Texas representative Beto O’Rourke.

Simonelli argues that any solution needs to incorporate both fight and flight options. “There is a need to rebuild our communities to stronger flood [and] hurricane wind standards as well as moving them inland,” which will be a “huge undertaking,” she said. “This should open a discussion about the future of disaster insurance, immigration policy, and disaster preparedness.”

“Win for Climate and the American People”

That climate change is a crisis that affects people around the world was common ground among the presidential hopefuls. “We are fighting for the survival of the Planet Earth,” Sanders said.

Scientists watching the debate voiced support for the town hall as a way to convey that message to voters.

“At the end of the day, this is a win for climate and the American people. We are finally at a stage where we can discuss and debate serious policy questions on ways to address climate change and not get stuck with inane questions like ‘Do you believe in climate change?’ that have long dominated this topic,” Ravikumar noted.

“As a researcher in this field, I wasn’t prepared to be ‘wowed’ by anyone, but what is important is that they are discussing climate change in some detail and candidates are taking this issue seriously,” said Simonelli.

Stokes called the event “unprecedented coverage of the climate crisis on mainstream national cable news.”

“I think we’ll have knockoff effects that we will be benefiting from for years to come,” she added.

Candidates will have a second chance to speak to a live audience about their climate change plans on 19–20 September at Georgetown’s Climate Forum cohosted with MSNBC.

Eos is a source for news and perspectives about Earth and space science, including coverage of new research, analyses of science policy, and scientist-authored descriptions of their ongoing research and commentary on issues affecting the science community.